scholarly journals Evolution and Ecology of Silent Flight in Owls and Other Flying Vertebrates

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Christopher J Clark ◽  
Krista  LePiane ◽  
Lori Liu
Keyword(s):  
Empirical Support ◽  
Aerodynamic Noise ◽  
Current Evidence ◽  
Anatomical Location ◽  
Bird Flight ◽  
Acoustic Signature ◽  
Apparent Relationship ◽  
Frictional Sound ◽  
New Perspective ◽  
Frictional Noise

Synopsis We raise and explore possible answers to three questions about the evolution and ecology of silent flight of owls: (1) do owls fly silently for stealth, or is it to reduce self-masking? Current evidence slightly favors the self-masking hypothesis, but this question remains unsettled. (2) Two of the derived wing features that apparently evolved to suppress flight sound are the vane fringes and dorsal velvet of owl wing feathers. Do these two features suppress aerodynamic noise (sounds generated by airflow), or do they instead reduce structural noise, such as frictional sounds of feathers rubbing during flight? The aerodynamic noise hypothesis lacks empirical support. Several lines of evidence instead support the hypothesis that the velvet and fringe reduce frictional sound, including: the anatomical location of the fringe and velvet, which is best developed in wing and tail regions prone to rubbing, rather than in areas exposed to airflow; the acoustic signature of rubbing, which is broadband and includes ultrasound, is present in the flight of other birds but not owls; and the apparent relationship between the velvet and friction barbules found on the remiges of other birds. (3) Have other animals also evolved silent flight? Wing features in nightbirds (nocturnal members of Caprimulgiformes) suggest that they may have independently evolved to fly in relative silence, as have more than one diurnal hawk (Accipitriformes). We hypothesize that bird flight is noisy because wing feathers are intrinsically predisposed to rub and make frictional noise. This hypothesis suggests a new perspective: rather than regarding owls as silent, perhaps it is bird flight that is loud. This implies that bats may be an overlooked model for silent flight. Owl flight may not be the best (and certainly, not the only) model for “bio-inspiration” of silent flight.

scholarly journals Evidence that the Dorsal Velvet of Barn Owl Wing Feathers Decreases Rubbing Sounds during Flapping Flight

2020 ◽  
Vol 60 (5) ◽  
pp. 1068-1079 ◽  
Author(s):  
Krista LePiane ◽  
Christopher J Clark
Keyword(s):  
Low Frequency ◽  
Flapping Flight ◽  
Aerodynamic Noise ◽  
Tyto Alba ◽  
Frequency Range ◽  
Entire Frequency Range ◽  
Bird Flight ◽  
Sound Levels ◽  
Barn Owls ◽  
Frictional Noise

Synopsis Owls have specialized feather features hypothesized to reduce sound produced during flight. One of these features is the velvet, a structure composed of elongated filaments termed pennulae that project dorsally from the upper surface of wing and tail feathers. There are two hypotheses of how the velvet functions to reduce sound. According to the aerodynamic noise hypothesis, the velvet reduces sound produced by aerodynamic processes, such as turbulence development on the surface of the wing. Alternatively, under the structural noise hypothesis, the velvet reduces frictional noise produced when two feathers rub together. The aerodynamic noise hypothesis predicts impairing the velvet will increase aerodynamic flight sounds predominantly at low frequency, since turbulence formation predominantly generates low frequency sound; and that changes in sound levels will occur predominantly during the downstroke, when aerodynamic forces are greatest. Conversely, the frictional noise hypothesis predicts impairing the velvet will cause a broadband (i.e., across all frequencies) increase in flight sounds, since frictional sounds are broadband; and that changes in sound levels will occur during the upstroke, when the wing feathers rub against each other the most. Here, we tested these hypotheses by impairing with hairspray the velvet on inner wing feathers (P1-S4) of 13 live barn owls (Tyto alba) and measuring the sound produced between 0.1 and 16 kHz during flapping flight. Relative to control flights, impairing the velvet increased sound produced across the entire frequency range (i.e., the effect was broadband) and the upstroke increased more than the downstroke, such that the upstroke of manipulated birds was louder than the downstroke, supporting the frictional noise hypothesis. Our results suggest that a substantial amount of bird flight sound is produced by feathers rubbing against feathers during flapping flight.

E-mass customization: Effects of self-congruity and functional congruity on consumer responses

2016 ◽  
Vol 44 (8) ◽  
pp. 1379-1394 ◽  
Author(s):  
Minjung Park ◽  
Jungmin Yoo
Keyword(s):  
Mass Customization ◽  
Online Survey ◽  
Empirical Support ◽  
Perceived Quality ◽  
Ideal Self ◽  
Self Monitoring ◽  
Consumer Responses ◽  
Online Shoppers ◽  
Functional Congruity ◽  
New Perspective

Following the increasing popularity of mass customization in the online retailing environment, we investigated the effects of self-congruity and functional congruity on consumer responses. Female online shoppers (N = 303) in South Korea participated in an online survey. The results showed that the match between ideal self-concept and the customized product was a strong determinant of emotional product attachment. Functional congruity influenced emotional product attachment and perceived quality, which, in turn, influenced behavioral intentions. We also observed a moderating role of self-monitoring, such that, for high self-monitors ideal congruity influenced emotional product attachment, whereas for low self-monitors functional congruity influenced emotional product attachment and perceived quality. Thus, we provided both empirical support for the effects of ideal congruity and functional congruity on consumer responses in an online mass customization context, and a new perspective for those seeking to enhance the effectiveness of mass customization.

scholarly journals Perceptual-Motor and Perceptual-Cognitive Skill Acquisition in Soccer: A Systematic Review on the Influence of Practice Design and Coaching Behavior

2021 ◽  
Vol 12 ◽  
Author(s):  
Fynn Bergmann ◽  
Rob Gray ◽  
Svenja Wachsmuth ◽  
Oliver Höner
Keyword(s):  
Systematic Review ◽  
Skill Acquisition ◽  
Empirical Support ◽  
Cognitive Skill ◽  
Systematic Search ◽  
Current Evidence ◽  
Evidence Based ◽  
Theoretical Frameworks ◽  
Cognitive Skill Acquisition ◽  
Coaching Behavior

Facilitating players' skill acquisition is a major challenge within sport coaches' work which should be supported by evidence-based recommendations outlining the most effective practice and coaching methods. This systematic review aimed at accumulating empirical knowledge on the influence of practice design and coaching behavior on perceptual-motor and perceptual-cognitive skill acquisition in soccer. A systematic search was carried out according to the PRISMA guidelines across the databases SPORTDiscus, PsycInfo, MEDLINE, and Web of Science to identify soccer-specific intervention studies conducted in applied experimental settings (search date: 22nd November 2020). The systematic search yielded 8,295 distinct hits which underwent an independent screening process. Finally, 34 eligible articles, comprising of 35 individual studies, were identified and reviewed regarding their theoretical frameworks, methodological approaches and quality, as well as the interventions' effectiveness. These studies were classified into the following two groups: Eighteen studies investigated the theory-driven instructional approaches Differential Learning, Teaching Games for Understanding, and Non-linear Pedagogy. Another seventeen studies, most of them not grounded within a theoretical framework, examined specific aspects of practice task design or coaches' instructions. The Downs and Black checklist and the Template for Intervention Description and Replication were applied to assess the quality in reporting, risk of bias, and the quality of interventions' description. Based on these assessments, the included research was of moderate quality, however, with large differences across individual studies. The quantitative synthesis of results revealed empirical support for the effectiveness of coaching methodologies aiming at encouraging players' self-exploration within representative scenarios to promote technical and tactical skills. Nevertheless, “traditional” repetition-based approaches also achieved improvements with respect to players' technical outcomes, yet, their impact on match-play performance remains widely unexplored. In the light of the large methodological heterogeneity of the included studies (e.g., outcomes or control groups' practice activities), the presented results need to be interpreted by taking the respective intervention characteristics into account. Overall, the current evidence needs to be extended by theory-driven, high-quality studies within controlled experimental designs to allow more consolidated and evidence-based recommendations for coaches' work.

scholarly journals Introduction to the Symposium: Bio-Inspiration of Quiet Flight of Owls and Other Flying Animals: Recent Advances and Unanswered Questions

2020 ◽  
Vol 60 (5) ◽  
pp. 1025-1035
Author(s):  
Christopher J Clark ◽  
Justin W Jaworski
Keyword(s):  
Force Production ◽  
Bird Flight ◽  
Ongoing Research ◽  
Predator Prey ◽  
Physical Mechanisms ◽  
Acoustic Signature ◽  
Gliding Flight ◽  
Prey Interaction ◽  
Animal Flight

Synopsis Animal wings produce an acoustic signature in flight. Many owls are able to suppress this noise to fly quietly relative to other birds. Instead of silent flight, certain birds have conversely evolved to produce extra sound with their wings for communication. The papers in this symposium synthesize ongoing research in “animal aeroacoustics”: the study of how animal flight produces an acoustic signature, its biological context, and possible bio-inspired engineering applications. Three papers present research on flycatchers and doves, highlighting work that continues to uncover new physical mechanisms by which bird wings can make communication sounds. Quiet flight evolves in the context of a predator–prey interaction, either to help predators such as owls hear its prey better, or to prevent the prey from hearing the approaching predator. Two papers present work on hearing in owls and insect prey. Additional papers focus on the sounds produced by wings during flight, and on the fluid mechanics of force production by flapping wings. For instance, there is evidence that birds such as nightbirds, hawks, or falcons may also have quiet flight. Bat flight appears to be quieter than bird flight, for reasons that are not fully explored. Several research avenues remain open, including the role of flapping versus gliding flight or the physical acoustic mechanisms by which flight sounds are reduced. The convergent interest of the biology and engineering communities on quiet owl flight comes at a time of nascent developments in the energy and transportation sectors, where noise and its perception are formidable obstacles.

A New Perspective: A Vulnerable Population Framework to Guide Research and Practice for Persons With Traumatic Brain Injury

2006 ◽  
Vol 20 (2) ◽  
pp. 141-157 ◽  
Author(s):  
Esther Bay ◽  
Grace J. Kreulen ◽  
Clarissa Agee Shavers ◽  
Connie Currier
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Chronic Disease Management ◽  
Community Integration ◽  
Empirical Support ◽  
Community Context ◽  
Community Based ◽  
New Perspective ◽  
Expensive Process ◽  
Community Systems

Recovery from traumatic brain injury (TBI) can be a tumultuous lifelong and expensive process. Guided therapies for community integration within community systems are a focus of treating therapists around the world, yet there are no published discussions concerning the most fitting community context. We propose a theoretical approach for practice and research using Flaskerud and Winslow’s conceptual model of vulnerable populations. Using the model constructs of health status, resource availability, and increased relative risk, we offer empirical support for proposed construct relationships applied to persons with traumatic brain injury. We then propose that interventions for health promotion, acute care, and rehabilitation or chronic disease management have a community focus, and we identify relevant goals for community-based practice and research.

scholarly journals Evidence base for psychological treatment of personality disorder – a narrative review

BJPsych Open ◽  
2021 ◽  
Vol 7 (S1) ◽  
pp. S278-S278
Author(s):  
Caoimhe Ni Shuilleabhain
Keyword(s):  
Personality Disorder ◽  
Psychological Treatment ◽  
Clinical Care ◽  
Treatment Strategies ◽  
Empirical Support ◽  
Evidence Base ◽  
Treatment Modalities ◽  
Current Evidence ◽  
Specific Patient ◽  
Current Evidence Base

AimsThis review critically appraises the up-to-date evidence base for psychological treatment of PD.BackgroundThe prevalence rate of any personality disorder (PD) in the general population has been estimated to be as high as 12% rising to over 70% in prison settings. PD is known to carry significant psychosocial and health burdens with increased mortality, increased suicide, increased substance misuse, increased crime, reduced capacity to work, poorer outcomes for comorbid mental disorders, dysfunctional engagement with services, and high economic costs through a high utilisation of healthcare systems. In the 1990s several manualised treatment strategies emerged, specifically for borderline PD. These include dialectical behaviour therapy, cognitive therapy, cognitive analytic therapy, mentalization-based therapy, transference-focused psychotherapy, and schema-focussed therapy.MethodUsing relevant search criteria, literature was identified through a search of the following databases: PubMed, EMBASE, and PsycINFO. Data were appraised and synthesised to provide a comprehensive overview of the current evidence base for psychological treatment of PD.ResultThe DSM-V defined Cluster B borderline PD has received the majority of attention. Increasing attention has been paid in recent years to the Cluster B antisocial PD. Cluster A (Paranoid, Schizoid, Schizotypal) and Cluster C PDs (Avoidant, Dependent, Obsessive Compulsive) have received relatively little attention with few studies to draw upon regarding the effectiveness of therapy. The remaining Cluster B personality disorders (Narcissistic and Histrionic) have been criticised as having poor construct validity, with a lack of rigorously designed treatment trials.A number of treatment protocols have gained empirical support. However, of those that have empirical support, there appears to be little demonstrable evidence to suggest superiority of any one of the evidence-based interventions over another. While specialised therapies are more efficacious than “treatment as usual” or treatment delivered by expert clinicians, when specialised therapies are compared with well-specified manualised general psychiatric care tailored to personality disorder, the results are different, with little consistent evidence demonstrating the superiority of specialised therapies.ConclusionCurrent evidence suggests that individual therapies do not differ substantially from each other or from structured clinical care that relies on generic change factors. This is in keeping with established psychotherapy outcome literature. Current evidence would indicate that common features across the proven treatment strategies should be emphasised and implemented well. There may be justification for added interventions from specific treatment modalities targeted to specific patient problems.

Uses and applications of docosahexanoic acid (dha) in pediatric gastroenterology: current evidence and new perspective.

2021 ◽  
Vol 17 ◽  
Author(s):  
David González Jiménez ◽  
Carlos Bousoño García ◽  
Juan Jose Diaz Martín
Keyword(s):  
Fatty Acids ◽  
Clinical Practice ◽  
Experimental Studies ◽  
Paediatric Population ◽  
Current Evidence ◽  
Pediatric Gastroenterology ◽  
Docosahexanoic Acid ◽  
Usual Clinical Practice ◽  
New Perspective ◽  
As Effects

: In this paper we will review the dietary allowances of these fatty acids in the paediatric population, and also the indications in different pathologies within the field of pediatric gastroenterology. Finally, we will try to explain the reasons that may justify the difficulty in translating the good results in experimental studies to the usual clinical practice. This "good results" may be too little to be detected or there are other causes but misinterpreted as effects of dha.

scholarly journals Exploring dynamic capabilities, intellectual capital and innovation performance relationship: evidence from the garment manufacturing

2019 ◽  
Vol 20 ◽  
pp. 123-136 ◽  
Author(s):  
Wendra Wendra ◽  
Ernie Tisnawati Sule ◽  
Joeliaty Joeliaty ◽  
Yudi Azis
Keyword(s):  
Intellectual Capital ◽  
Dynamic Capabilities ◽  
Small And Medium Enterprises ◽  
Empirical Support ◽  
Partial Least Square ◽  
Innovation Performance ◽  
Least Square ◽  
New Perspective ◽  
Medium Enterprises ◽  
Garment Manufacturing

The notions of dynamic capabilities, intellectual capital, and innovation performance have been examined in many competitive advantage scholarly papers. However, there have been small numbers of management studies that consider the link of dynamic capabilities and intellectual capital in respect of innovation performance. Previous studies tend to argue that dynamic capabilities played a mediator or moderator role on intellectual capital and innovation performance linkage. Therefore, this study seeks to propose a new perspective that dynamic capabilities are the antecedents of intellectual capital leading to innovation performance. Thus, the rationale for this study is to propose a conceptual model and to provide empirical support on the mediator role of intellectual capital in dynamic capabilities and innovation performance linkage. By using accidental and snowballs sampling techniques, this study distributed questionnaires to 297 small and medium enterprises of the garment manufacturing in Indonesia. Partial least square offers the main statistics methodology for data analysis. Results show that dynamic capabilities had a significant influence on intellectual capital and innovation performance. Moreover, intellectual capital partially mediated dynamic capabilities’ influence on innovation performance. Therefore, it is expected that organisations should grow, implement and maintain their dynamic capabilities in order to improve their intellectual capital and innovation outcomes. Lastly, some future studies are suggested.

DSM Applications to Young Children: Are There Really Bipolar and Depressed Two-Year-Olds?

2017 ◽  
Author(s):  
Harold Kincaid
Keyword(s):  
Bipolar Disorder ◽  
Young Children ◽  
Psychiatric Disorders ◽  
Practical Importance ◽  
Empirical Support ◽  
Current Evidence ◽  
Psychiatric Diagnoses ◽  
Psychoactive Drugs ◽  
Small Children ◽  
Current State

Scientific commonsense would suggest that very young children cannot have psychiatric disorders such as bipolar disorder or major depression since they do not have the level of development to express the complex characteristics of these disorders. This chapter provides a detailed survey of current evidence supporting this common sense claim. The chapter first gives a general perspective on DSM that will be applied in looking at childhood psychiatric diagnoses and should be of some interest in its own right. I argue that there are some DSM based categorizations--those of major depressive disorder and bipolar disorder--that have substantial empirical support. I look at these two classifications as the best case for pediatric psychiatric disorders. I argue that this best case fails given our current state of knowledge, raising doubts in general about psychiatric diagnoses in small children. This conclusion has practical importance, since small children are increasingly being given powerful psychoactive drugs.

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